Panorametry: suggestion of a method for mandibular measurements on panoramic radiographs

<p>Abstract</p> <p>Background</p> <p>Orthopantomography (panoramic radiography) has been used for the study of measurements involving particularly the prediction of the eruption of impacted lower third molars and analyses of measurements of the ramus and head of mandible. The discrepancies involved with the projection of this radiographic image has stimulated the search for further ways to use it, particularly in orthodontic treatments and oral and maxillofacial surgeries. The author proposes a graphimetric method for the mandible, based on panoramic radiography. The results are expressed in linear and angular measurements, aiming at bilateral comparisons as well as the determination of the proportion of skeletal and dental structures, individually and among themselves as a whole. The method has been named Panorametry, and allows measurement of the mandible (Mandibular Panorametry) or the posterior mandibular teeth (Dental Panorametry). When combining mandible and maxilla, it should be referred to as Total Panorametry. It may also be used, in the future, with Cone Beam computed tomography (CT) images, and in this case it may be mentioned as CT Panorametry.</p

Dimensões nasofaringeanas e faciais em diferentes padrões morfológicos Nasopharyngeal and facial dimensions of different morphological patterns

OBJETIVO: o presente estudo propõe-se a comparar as dimensões da nasofaringe e as características esqueléticas avaliadas por exame cefalométrico, em indivíduos com padrões morfológicos distintos. MÉTODOS: foram utilizadas 90 telerradiografias de pacientes de ambos os gêneros, de 12 a 16 anos de idade, as quais foram igualmente divididas em três grupos distintos, referentes aos padrões morfológicos - braquifacial, mesofacial e dolicofacial. Foram realizadas medições específicas da região nasofaringeana (ad1-Ptm, ad2-Ptm, ad1-Ba, ad2-S0, (ad1-ad2-S0-Ba-ad1/Ptm-S 0-Ba-Ptm) X 100, e Ptm-Ba) e relativas ao padrão esquelético da face. RESULTADOS: observou-se que os pacientes dolicofaciais apresentaram menor profundidade sagital óssea (Ptm-Ba) e da via aérea da nasofaringe (ad1-Ptm e ad2-Ptm). Sugere-se que essas diferenças estejam relacionadas a um posicionamento relativamente mais posterior da maxila, comum a esses pacientes. Todavia, não foram detectadas diferenças quanto à espessura de tecido mole na parede posterior nasofaringeana (ad1-Ba e ad2-S0), ou à sua proporção em relação a toda a área delimitada para a nasofaringe [(ad1-ad2-S0-Ba-ad1/Ptm-S 0-Ba-Ptm) X 100]. CONCLUSÃO: sugere-se, portanto, que as características faciais de excesso vertical encontradas em pacientes dolicofaciais podem ocorrer, dentre outros fatores, em virtude da obstrução da via aérea nasofaringeana, uma vez que tais dimensões se apresentaram menores para os dolicofaciais.<br>OBJECTIVE: The purpose of this study was to compare the dimensions of the nasopharynx and the skeletal features-evaluated by cephalometric examination-of individuals with different morphological patterns. METHODS: Were used cephalometric radiographs of 90 patients of both genders, aged 12 to 16 years, which were also divided into three distinct groups, according to their morphological patterns, i.e., brachyfacials, mesofacials and dolichofacials. Measurements were performed of specific nasopharyngeal regions (ad1-Ptm, ad2-Ptm, ad1-Ba, ad2-S0, (ad1-ad2-S0-Ba-ad1/Ptm-S 0-Ba-Ptm) X 100, and Ptm-Ba), and relative to the facial skeletal patterns. RESULTS: Dolichofacial patients were found to have lower than average bone depth sagittally (Ba-Ptm) and lower nasopharyngeal airway depth (ad1-Ptm and ad2-Ptm). Arguably, these differences are linked to a relatively more posterior position of the maxilla, typical of these patients. No differences were found, however, in the soft tissue thickness of the posterior nasopharyngeal wall (ad1-Ba and ad2-S0), or their proportion in the whole area bounded by the nasopharynx ((ad1-ad2-S0-Ba-ad1/Ptm-S 0-Ba-Ptm) X 100). CONCLUSIONS: We therefore suggest that the excessively vertical facial features found in dolichofacial patients may be the result, among other factors, of nasopharyngeal airway obstruction, since such dimensions were shown to be smaller in dolichofacials